The aforementioned lock comprises a locking mechanism that contains a rotary latch and at least one pawl with which the rotary latch can be locked in a closed position by locking surfaces of the pawl and rotary latch. Locking surfaces refers to surfaces on the pawl and rotary latch abutting to ensure locking of the locking mechanism and that result in overlapping. In a closed position the rotary latch can keep a door or flap closed, so that the door or flap cannot be opened. If the rotary latch is in an open position, the locking bolt can leave the locking mechanism and the door and flap can be opened.
A rotary latch contains a load arm and a collecting arm. In case of a locked locking mechanism the load arm prevents a locking bolt of a door or flap from disengaging from the locking mechanism. If a door or flap is closed, the closing bolt is moved against the load arm moving it and thus also the rotary latch in the direction of the closed position.
Publication DE 10 2010 003 483 A1 discloses a locking mechanism, in which the rotary latch initiates an opening moment in the pawl when the pawl latches the rotary latch in the fully closed position. The rotary latch can for instance initiate such a moment in the pawl as a result of a door sealing pressure and/or due to a pretensioned spring that can turn the rotary latch into its opening position and/or can initiate such a torque in the pawl by opening of a respective door or flap. The pawl can be moved out of its locked position into its detent position by an opening moment. In order to reliably prevent this in the event of a locked locking mechanism, the arrangement also contains a blocking lever that can block the movement of the pawl out of its detent position. To open such a locking mechanism, the blocking lever is moved out of its blocking position with the aid of the release lever. Generally the opening moment initiated by the rotary latch in the pawl suffices to unlock the locking mechanism, i.e. to open it.
In a locking mechanism with the aforementioned opening moment it can happen for a variety of reasons that the opening moment does not suffice to move the pawl out of its locking position. In order to ensure that the locking mechanism opens also in the event of such a malfunction, a tappet is provided that is, for instance, attached to the release lever and/or the intermediate closed position pawl disclosed in DE 10 2010 003 483 A1. Such a tappet should move the pawl out of its locking position in particular if the pawl is unable to leave the locking position solely as a result of the opening moment.
In order for the tappet to be able to open the locking mechanism, it must be possible to pivot the tappet arranged, for instance, on the release lever by a sufficiently large angle. In general, an angle of between 20° to 30° suffices, such as approx. 25°, for the pawl to be moved out of its locking position solely by means of the tappet.
A release lever of a locking mechanism is generally moved by actuation of a handle in order to release a locking mechanism. The handle can be an internal door handle or an external door handle of a motor vehicle. Such a handle is generally connected to the release lever via a rod assembly or a Bowden cable in order to move the release lever upon actuation of the handle. Where the rod assembly or the Bowden cable wear out due to ageing, this can also reduce the pivot range by which the release lever can be pivoted by actuation of a handle. It may then not be possible to reliably open the locking mechanism.
In particular in case of a motor vehicle only limited space is available. Experts also, in particular in case of motor vehicles, endeavor to reduce weight. In case of locks it is in particular in motor vehicles important that the locks are small and easily produced.